After felled timber in the form of logs has been passed through a lumber mill and cut into usable pieces of lumber, many of these pieces of lumber are treated with a preservative in the mill. This is commonly accomplished by running the cut lumber through a vat of liquid preservative and then removing the treated pieces of lumber on an endless conveyor. At that time, a quality control stamping or printing of various indicia is performed on the lumber so that users of the cut and treated lumber will have descriptive information readily available on the lumber itself. In particular, this information commonly includes the specifications and certification trademark of the American Wood Preservation Bureau; the name of the treatment company and its trademark; the amount of treatment given to the lumber; the name or number of the mill manufacturing the cut lumber; and the trademark and name of Timber Products Inspection & Testing Service, Inc.. The stamping is usually done on one end of a piece of lumber about 18 inches to two feet from the end, or in certain pieces of lumber about 18 inches to two feet from both ends.
Presently, the larger mills utilize highly automated, expensive and large stamping machines. However, many mills still utilize an old hand-held stamping device comprised of a curved rigid plate, having a handle on one side and a rubber stamp pad on the other. This prior art device is extremely slow to use since the imprint from the stamp pad must be rolled onto the lumber from the curved support plate. In addition, such a device is hard on the hands of the operator and often results in an inaccurate or incomplete stamping since a minimum amount of pressure must be applied from the stamp pad to the cut lumber. Moreover, in those situations where long pieces of lumber must have two stamps, one at each end, two people must perform the stamping operation since the hand-held device is not large enough to conveniently stamp both ends.
Although there have been in the prior art various marking or stamping hammers, these do not disclose or utilize a rubber stamp pad which is required for such a quality control stamping of cut pieces of lumber. Such prior art devices are disclosed in the following U.S. Pat. Nos. 1,034,516, issued to Samberg on Aug. 6, 1912; 1,084,207, issued to Graham et al on June 10, 1913; 1,078,601, issued to Matthews on Nov. 11, 1913; 2,857,839, issued to Jamieson on Oct. 28, 1958; and 3,620,159, issued to Gould on Nov. 16, 1971. In addition, there is a design patent U.S. Pat. No. Des. 248,417, issued to Pennington, the inventor herein, on July 4, 1978; however, the rubber stamp hammer head disclosed therein is too flexible to provide the quality control stamping outlined above.